1. Field of the Invention
The present invention relates to locator devices and more particularly pertains to a new locator system for locating persons or articles in potentially hazardous situations or environments.
2. Discussion of the Prior Art
Conventional approaches used to locate individuals or articles in hazardous situations are based on simply looking for or listening for the individual or article. These approaches are effective for some “missing first responder” scenarios, but there are occasions when a missing individual or article may go unnoticed. One scenario where this is possible is in a collapsed or burning building. A noisy environment accompanying damage control or rescue operations in bad weather or at night makes it difficult to see or hear a missing person. The problem is compounded when many people are responding and considerable time may pass before one person is recognized as missing.
A variety of locator systems are described in the prior art. The prior art for locating persons or articles includes, for example, U.S. Pat. No. 6,545,606 (rescue beacon), U.S. Pat. No. 6,539,393 (location data logging), U.S. Pat. No. 6,501,378 (item locator), U.S. Pat. No. 6,643,516 (portable telephone locator), U.S. Pat. No. 6,462,658 (illuminated/sound producing object locator), U.S. Pat. No. 6,611,232 (vehicle lock box locator), U.S. Pat. No. 6,630,892 (danger alert system), U.S. Pat. No. 6,634,959 (golf ball locator), U.S. Pat. No. 5,677,673 (article locator with loudspeaker); U.S. Pat. No. 5,939,981 (item locator with audio speaker), U.S. Pat. No. 4,101,873 (locator with audible response) and U.S. Pat. No. 5,680,105 (color coordinated locator with beeper). While the methods and devices disclosed in these patents do fulfill their own narrow objectives, these patents do not disclose an economical, reliable, truly robust and easy to use locator system suitable for use in finding persons or articles in hazardous situations such as a burning or collapsed structure.
A number of other patents have also disclosed systems for person or article location; for example, U.S. Pat. No. 4,151,525 by Strauch et al., describes an analog radio system for locating a given object. The system displays angle and range data regarding the position of an object in a reference frame. This invention suffers from the following limitations: it has a complex design, it is limited to locating aircraft as it is extremely difficult for a person to orient oneself along a displayed particular angular displacement and the displayed range does not carry any particular significance to a person who is trying to locate an item or a person.
U.S. Pat. No. 4,476,469 by Lander, describes an analog apparatus which can assist in locating an object. It comprises a searcher and a locator attached to the object. The locator gives an audible beep when it is positioned by the searcher. This invention is limited to assisting in locating objects within a short range, up to 6 meters range. Hence, it is only suitable for normal domestic and office conditions. It does not display exact direction of the object location apart from the audible bleep which is generated from the locator attached to the object when it is positioned. In addition, it does not give any visual alerting means to assist in locating the object.
U.S. Pat. No. 4,673,921 by Saito et al., describes an apparatus for finding the location of a car within a large area. In this invention the transmitter is attached to the car and the receiver is portable. Search is carried out until maximum level of the signal generated from the transmitter is displayed. This invention suffers from the following drawbacks: the transmitter is always radiating a signal which represents a drain on the apparatus battery, it is complex in design and construction, it needs a central processing units with sophisticated algorithms and it is impractical.
U.S. Pat. No. 5,631,641 by Howe, describes a vehicle locator system which is integrated into the electrical system of a vehicle. This locator is designed specifically for bird hunters. It emits an audible alarm after the elapse of a specified delay time set up by the hunter when leaving the vehicle. This invention is limited in its application. It does not give any visual alerting means to assist in locating the object, it is an integrated part of the vehicle electrical system and not a stand alone device and it is activated whilst the hunter is away from the vehicle, thus representing a constant electrical load drainage on the vehicle battery.
U.S. Pat. No. 5,689,238 by Cannon et al., describes a method of locating objects by attaching electronic tags to these objects. An electronic tag is identifiable by a unique response code. To locate the object, the response code is entered via an interrogator. The interrogator sends a signal that causes the tag to emit a sound. This invention is only operational if the identifying unique response code stored on the electronic tag is not tampered with in any way. Also if this code is inadvertently erased, the locator will be obsolete.
U.S. Pat. No. 5,786,758 by Bullock, describes a vehicle locator system combining a remote transmitting unit and a vehicle mounted receiving unit actuating a light source mounted on the vehicle's exterior to facilitate the location of the vehicle by the searcher in a crowded or dimly lit places. This system is also capable of selectively actuating the vehicle's horn. This invention suffers from the complexity in mechanical structure and the interference with the car exterior. In addition, the partially lowered vehicle window necessary for installing the vehicle's exterior light source represents a security issue for the vehicle. In addition, the light source may accumulate dirt and grit and due to being subjected to the external environmental conditions may malfunction frequently.
U.S. Pat. No. 5,714,932 by Castellon et al. describes a radio frequency security system with direction and distance locator. The radio frequency security system includes a central control unit and a plurality of portable transmitters which are in radio frequency communication with the central control unit. The system can be used to detect if a child or an inanimate object has crossed a specified boundary security region. It can also yield information regarding range and direction. This invention has a complex design as it includes a central control unit containing a central processing unit and its associated memory devices, a directional detection circuit, a threshold detection circuit, a distance measuring circuit, a keypad input device, an antenna system, an identification circuit and several displays.
U.S. Pat. No. 6,344,797, by Hosney, describes a system configured to provide an audio or visual alert to assist in locating an object, animal or person by triggering an audio buzzer, audio message, music or visual flashing display unit when the object, animal or person is located. An alternative embodiment also gives the searcher a facility for finding the direction of the object, animal or person to be located. A third embodiment additionally permits a searched-for person to know the direction of the searcher.
All of these prior art systems have proven inadequate in many hazardous situations, however, and for a number of reasons. A fire's flame, being an ionized moving plasma of sorts, plays havoc with conventional radio transmission when using conventional transmitted signals, and rescuers or emergency personnel, when under great stress, require information that is immediately discernable to permit quick decisions in what may be a life or death situation. These challenges have rendered the prior art systems unsuitable for use in many hazardous situations.
There is a need, therefore, for an economical, reliable, truly robust and easy to use locator system and method suitable for use in finding persons or articles in hazardous situations such as a burning or collapsed structure.